The present invention relates generally to fluridone-related compositions and methods that are useful, for example, in herbicidal applications.
As further background, aquatic plants very commonly arise as undesired weeds in waters and wetlands in the United States of America and elsewhere. Three such exotic weeds are hydrilla, curlyleaf pondweed, and watermilfoil, including Eurasian watermilfoil. These weeds often present problems in ponds, lakes, and other water bodies.
Fluridone is a bleaching herbicide that has been used in the control of aquatic weeds. Commercially, fluridone is available as a liquid formulation in a suspension concentrate form, in which fluridone solids are suspended in an aqueous carrier formulation. Fluridone has very limited solubility in a wide variety of solvent systems, and efforts to develop and market this agent have focussed on relatively highly concentrated solid suspension concentrates or solid forms.
Formulation stability is a key factor in the successful development of herbicidal formulations. The development of storage-stable, flowable liquid formulations has presented many difficulties over the years. Attempts to prepare such formulations meet with a variety of failures, commonly involving phase separation. A variety of phase separations may occur including as examples crystallization, sedimentation, creaming, Ostwald ripening, and the like. Moreover, in the case of so-called “emulsifiable concentrate” formulations, solubility issues relative to the active agent and the organic solvent system used create difficulties. For example, it can be difficult to develop an organic solvent system that will stably solvate the herbicidal active agent at acceptable levels during storage and yet form a beneficial emulsion when added to water that effectively delivers the active agent to the target plants.
In view of the background in this area, needs exist for improved and/or alternative formulations of fluridone and other like herbicidal agents.